Currently doing research, might get type 1 and type 2, i understand type 2 usually requires double pole breakers to work.

For type 1 can i connect it directly to the 2 live wires coming into the panel secured by screw?

For type 2 i dont have any free breaker spots, can replace 2 single poles with a double pole and then share it with the existing wire?

I moved to Mexico and am in a rental for about 6 mo, i do have type 3s on my TVs etc; but nothing for appliances, there arent really licensed contractors or requirements, i do have lots of experience installing 220v for welders and such so i am familiar with panels.

Texthttps://i.stack.imgur.com/PvhPs.jpg Texthttps://i.stack.imgur.com/FUJMw.jpg

  • Can you post a photo of the label on the inside of the panel's door please? Dec 27, 2020 at 22:50
  • I just put it in original post
    – xboxhaxorz
    Dec 28, 2020 at 0:26
  • If you're renting then you don't get to touch the panel without both a) permission from landlord, and b) permission from local authority. Can't speak to MX but in US nobody can work on a rental unit except a licensed electrician. If any tenant of mine took the cover off a panel, they'd get their walking papers. Dec 28, 2020 at 1:19
  • Hence the reason i specified Mexico, there are no real rules and if there are they arent enforced
    – xboxhaxorz
    Dec 28, 2020 at 1:30
  • 2
    @xboxhaxorz -- you have access to a main disconnect that turns all power off to this panel, right? Dec 28, 2020 at 2:02

2 Answers 2


I'd pick two of those 20s and swap them for a 20-50-50-20 triplex breaker

Since your panel is listed and labeled to accept tandem/"double stuff" breakers in all positions, and looks to be uniformly configured with 20A breakers, we can take two adjacent 20A breakers in the panel and switch them out for a MP22050CT (if you can find it) or Q22050CT (if you can't find the Murray part) triplex breaker, then land the two existing 20A circuits you replaced on the two outer poles. You can then install your Type 2 SPD, landing the hots on the two 50A inner poles of the triplex breaker, the neutral on the right-hand neutral bar, and the ground on the left-hand ground bar. (Note that you'll need to use a SPD that has separate neutral and ground wires coming out; some SPDs only provide two hots and a neutral and thus can't be used on a subpanel.)

And I'd clean up those double taps while I was at it

While I was in here, I'd clean up those two double taps on the bottom-left and bottom-right breakers, as all that takes is a couple of pigtails of 12AWG wire and wirenuts suited for 3 12AWG wires. Take each double-tap out of the breaker terminal screw, nut a pigtail to the twisted ends of the two wires, and land that pigtail on the breaker terminal screw the double-tapped wires once went to. Repeat for the other breaker, and once that and the SPD install are done, you can button things up, turn the main breaker back on, and call it a day!

  • That all makes sense and i did a google search for double taps to understand, and it seemed safer that way. I will check the stores if they have those appropriate breakers, otherwise ill try a few tandems. I was looking at the Siemens FS140 and in the manual it mentions 20a breakers, whereas you mentioned 50. For some reason they didnt mention double pole, im guessing its assumed, but im sure many DIYers might not realize.
    – xboxhaxorz
    Dec 28, 2020 at 22:39
  • @xboxhaxorz -- I usually use the Eaton CHSPT2ULTRA as my reference for Type 2 SPDs, and it uses a 50A breaker. For your FS140, you can use a Q22020CT instead Dec 28, 2020 at 23:26
  • Great. Appreciated. I am covered on type 2, if i wanted to do type 1 would i just connect it to the same screw points as the live wires?
    – xboxhaxorz
    Dec 29, 2020 at 0:13
  • @xboxhaxorz -- I wouldn't bother with a type 1 in your situation: the main lugs on a panel aren't listed for double-tapping, and most type 1s are not fitted with separate grounds and neutrals which means they can't be used away from the service entrance Dec 29, 2020 at 0:32

The surge protection needs to be on it's own breakers. The panel you have you can install tandem breakers in place of the full size breakers to make room for the new breaker needed.

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